Leadframes - Semiconductor Leadframes

What is a leadframe? A leadframe is a thin layer of metal that connects the wiring from tiny electrical terminals on the semiconductor surface to the large-scale circuitry on electrical devices and circuit boards. Leadframes are used in almost all semiconductor packages.

Leadframes manufactured by Advanced Chemical Etching are used in many industry sectors including semiconductors, relays, glass-to-metal seals and medical applications such as implantable devices and hearing aids. The significant advantage of ACE photo etched leadframes is the ability to produce large quantities of product with less tooling `Wear’ so the last lead frame is exactly the same as the first leadframe. Changes to the photo tooling can be very quickly implemented and the modification to these tools is significantly less expensive than traditional hard tooling. The process is ideal for manufacturing from prototype through to production quantities.

Materials

Plating

Lead free plating materials include Silver, Nickel, Gold, depending upon the customer's specific electrical and thermal conductivity requirements. Since the leadframe is the main conduit from which heat flows from the chip to the circuit board, ACE tailors the material to maximize the devices operating life for any given application or environment.

Capability

ACE manufactures high density etched semiconductor leadframes with complex and precise profiles with ultra-fine pitches, allowing for high pin count. When the semiconductor leadframe is photo etched there is no stress induced into the leadframe as with conventional manufacturing methods. Most significant is the fact that ACE’s photo etching process can be used for leadframes that are too complicated or intricate for other manufacturing methods. Dimensions can be held to extremely tight tolerances, with no burrs or other surface irregularities. ACE’s etched leadframes range in thickness from 0.010mm (0.0004”) to 1.5mm (0.060”) thick, with features as small as 0.1mm (0.004”) on 0.2mm (0.008”) pitches, creating a semiconductor leadframe that is strong enough to be handled yet flexible enough to allow bending/down setting when required. Rapid prototypes can be produced in a matter of days rather than weeks allowing customers to get their design to market extremely quickly.

Greater Economy

The Photo Tooling we use is highly accurate but also very economical when compared to the cost of conventional press tools. Small to medium volume manufacture which hard tooling makes prohibitively expensive becomes an economic proposition with photo / chemical etching. The photo tooling costs for highly complex designs are no more expensive than for simple ones, which is certainly not true of hard tooling which can cost several hundred thousand pounds.

Faster Speed

Conventional hard tooling can take weeks and even months to manufacture, whereas photo tooling direct from digital data can be produced in hours. This enables finished product to be produced in days rather than the months it takes using press tooling.

Improved Flexibility

Low cost of photo tooling gives designers the opportunity to modify and optimise leadframe design without the huge financial implications of modifying or replacing hard tooling. With the cost of modification being so low, designers do not face a significant cost penalty when seeking to optimise a design.

Lower Risk

Where the cost of hard tooling is amortised, the success of the project is dependent on quantity targets being achieved. Until volumes are achieved, the up-front tooling cost is carried as a risk. By initially using photo / chemically etched leadframes, the success and popularity of the device can be assessed before a capital investment decision becomes necessary ... removing risk from the development process.